But if we investigate the subject by the balance, a case occurs in which, without any addition or subtraction of matter, a substance will appear more… - Jean Rey

I imagine there are many persons who would have been startled (effarouchées) at the mere statement of this answer, had I given it in the outset, that will now receive it willingly, being, as I may say, tamed (apprivoisées) and rendered tractable, by the evident truth of the preceding essays. For doubtless they whose minds were preoccupied with the opinion that air is absolutely light, would have rushed to the encounter, exclaiming, Why do we not extract heat from cold, white from black, light from darkness, if from air, a thing absolutely light, we can extract so much weight? And they, who might have given credit to the weight of air, would have been unable to persuade themselves, that it could ever increase the weight of a substance balanced in itself.

[W]e must not only inquire whence these seven ounces are derived, but, moreover, whence that which has replaced the loss of weight, necessarily arising from the enlargement of volume of the tin, by its conversion into calx, and from the vapours and exhalations that have escaped.

God, creating the universe, neither made it perfectly like Himself, nor perfectly unlike, for He, being One, has made the world as not one, from the diverse multiplicity of its innumerable parts, ordaining, nevertheless, that they should collect into a certain unity by their exact contiguity. The upper world has no connexion with this subject; the lower, and elementary world, owes this contiguity to the weight divinely impressed on its parts, aided by the subtle fluidity of some of its simple bodies. It is by this quality, with which the matter of the four elements is more or less invested, that they are separated from one another, and each transported to its proper place, as the generation of compounds, and the beauty of the universe requires.